Neighbor is building without our consent - is it legal?

Hello,

I have a question about building law.
We have been living in a semi-detached house in Baden Württemberg for about 7 years.
Our adjacent neighbor has now asked us if we mind if they use an existing building envelope for an extension that directly borders our property line. I will try to illustrate this simply:
..|..
H|H
The upper line symbolizes the extension (without a gap, the dots have no meaning), which will be built about 5m long and about 7m high.
Our neighbor also told us that he actually does not need to ask us, which is kind if that is true and we do actually have any influence on it.
However, this is a shock to us, as this huge wall practically walls us in. Where before there was a clear view of the sky from the terrace and a 180cm high hedge marked the boundary, we will now be looking at a wall and the sun will probably disappear around 2:00 pm.

Can it be that this is lawful without our consent?
We would never have bought the house like this.
For us, this would be a reason to move out, but the loss in value would be considerable. Who buys something like that?

We would appreciate an answer.

Simon

At the border there is a small wall (approx. 2m long), on which our roof and the neighbor's roof rest or slope off. After that, there is a thuja hedge on the border. Under the roof are the terraces, which protrude about 1m below the roof.

Regards and thanks, Simon

Hello Simon,

There is a small wall (approx. 2m long) on the boundary, on which our and the neighbor's roof rest or run off. After that, there is a thuja hedge on the boundary. Under the roof are the terraces, which protrude about 1m under the roof.

Ok – assuming I interpret your point drawing correctly:

Building law applies throughout Germany, BW in my opinion makes no exception. Accordingly, boundary construction is only permitted for semi-detached or terraced houses; as exceptions, garages or carports which – unless another building envelope is specified by the planning office – must also be placed on the boundary. Recently, garages and/or carports can optionally be set on or 1.0 – 3.0 m from the property boundary – unfortunately, not all building authorities are up to date with the current state building regulations on this point; but that is just as a side note.

What you describe here is, in my opinion, a disguised backland development on the property boundary. Unless the valid development plan provides for this development – and I can hardly imagine otherwise, since the construction measure dates back almost 8 years and the development plan had to be observed accordingly – your neighbor is necessarily dependent on your consent => adjoining owner’s consent. The crucial question is whether the building planning office responsible for you would even approve this desired extension measure of your neighbor.

Suggestion: go to the building planning office with your neighbor’s request and your former building application documents, they usually have their public day on Thursday. Present the construction project brought to you by your neighbor and have it explained to you from first hand what can be built without and with your consent – if at all. All other attempts at explanation will not help you, because no one here knows the exact situation, the development plan, etc., and therefore answers here can easily mislead you.

Kind regards

Thank you very much for the detailed response, I will take your advice to heart.

Regards Simon